1. Field of the Invention
The present invention relates to power generating systems and more particularly to a small power generating system including a turbine and a power generator.
2. Description of the Related Art
JP-A-2003-286862 discloses a micro-turbine power generating system in which with high-speed rotation of turbine by a gas (fluid), a permanent magnet type rotor of a power generator is rotated at high speeds together with the turbine. Rotation of the rotor induces voltage on a stator coil of the power generator so that electrical power is generated.
A stator of the power generator includes an iron core and a stator coil wound on the iron core in the foregoing system. In this arrangement, core loss (particularly, eddy-current loss) in an iron core is increased with increase in a rotational speed of the rotor of the power generator. The core loss is proportional to a square of the frequency. Accordingly, the core loss increases during high-speed rotation of the rotor, thus constituting a factor interrupting high-speed rotation of the rotor. This prevents improvement in power generation efficiency.